The greatest physicist of the 20th century. Einstein was born in a Jewish family in Ulm, Germany. Influenced by his uncle as an engineer, he was enlightened by natural science and philosophy since he was a child. 1896, Einstein entered the normal department of Zurich University of Technology to study physics, and obtained Swiss nationality in 190 1 year. The following year, he was hired as a technician by the Swiss Patent Office in Bern, engaged in technical appraisal of invention patent applications. He used his spare time to engage in scientific research and made historic achievements in 1905. 1909, Einstein left the Swiss Patent Office and became an associate professor of theoretical physics at the University of Zurich; 19 12 became a professor at his alma mater, Zurich University of Technology; 19/kloc-returned to Germany in 0/4, and served as the director of the Institute of Physics of Emperor William and a professor at the University of Berlin. After the establishment of the fascist regime, Einstein was persecuted and forced to leave Germany. 1933 moved to the United States and served as a professor at Princeton Institute of Advanced Studies until 1945 retired.
Einstein is one of the most creative and intelligent figures in human history. He created four fields of physics in his life: special relativity, general relativity, cosmology and unified field theory. He is one of the main founders of quantum theory, and has also made great contributions to the theory of molecular motion and quantum statistics.
1905, Einstein published a paper on electrodynamics of moving objects, put forward the principle of relativity in a special sense and the principle of invariance of light speed, and established the special theory of relativity. On this basis, he further obtained the mass-energy formula E=mc2 with the same mass and energy. The special theory of relativity reveals the unity of space and time, as the unity of mechanical motion and electromagnetic kinematics as the existing form of matter, further reveals the unity of matter and motion, and lays a theoretical foundation for the utilization of atomic energy.
19 15, Einstein established the general theory of relativity, which further revealed the relationship between time and matter in four-dimensional space. According to the gravitational theory of general relativity, he concluded that light travels along a curve rather than a straight line in the gravitational field. This prediction was confirmed in the observation of solar eclipse by British astronomers in 19 19. From 65438 to 0938, Einstein made great progress in the motion of general relativity, and deduced the motion equation of objects from the field equation, thus further revealing the unity of space-time, matter, motion and gravity.
Einstein made great contributions to quantum theory. 1905, he put forward the hypothesis that the spatial distribution of energy is discontinuous, and thought that the energy at the speed of light is quantized in the process of propagation, absorption and production, and successfully revealed the photoelectric effect. This is the first time in history that the fluctuation of radiation and the unity of particles have been revealed in the process of human understanding of nature. 19 16 Einstein put forward the theory of stimulated radiation in his article Quantum Theory of Radiation, which laid a theoretical foundation for today's laser technology.
After the general theory of relativity, Einstein explored the unified field theory of the universe, gravity and electromagnetism. In order to prove the static distribution of celestial bodies in space, a finite and infinite static universe model is proposed based on the gravitational field, which is unstable. The motion of galaxy separation can be predicted from the gravitational field equation and later observed by astronomy.
Einstein loved music and thought that his performance in playing violin was better than that in physics. Einstein died at Princeton. He respects his wishes, does not erect a monument, does not hold any activities, and his ashes are scattered in a place that will always be kept secret from others. Max Born (1882- 1970), a German theoretical physicist and one of the founders of quantum mechanics, was born in breslau. 190 1 year entered the university of bryce, 1907 received his doctorate. 19 12 was employed as a lecturer at the university of g? ttingen, and 192 1 was appointed as the head of the department of physics and professor of theoretical physics at the university of g? ttingen.
After 1920, Born made a long-term systematic study of atomic structure and its theory, and the young Heisenberg was his teaching assistant and collaborator at that time. The Austrian physicist Schrodinger founded wave mechanics in 1926. At the same time, Born and Heisenberg established matrix mechanics by using matrix as a mathematical tool. Later, it was proved that matrix mechanics and wave mechanics are different forms of the same theory, which are collectively called quantum mechanics. Born made a statistical explanation of the physical meaning of wave function from the analysis of specific collision problems, that is, the quadratic term of wave function represents the probability of particle appearance. Because of this contribution, he won the 1954 Nobel Prize in Physics.
With the introduction of quantum mechanics, the University of G? ttingen became the international research center of theoretical physics at that time. Under the leadership of Born, the Gerdingen School of Physics, which is comparable to Bohr's Copenhagen School, was formed.
Born made a systematic study of solid theory, and wrote a paper on crystal vibration energy spectrum with von Kalman as early as 19 12. 1925, he published a book about crystal theory, and started a new discipline-lattice dynamics. Born published more than 300 papers and nearly 30 books in his life. The book Lattice Dynamics, which he co-authored with student Huang Kun, was praised as a classic work of related theories by academic circles.
1933 when Hitler came to power, Born was persecuted because of his Jewish descent, went into exile in Britain, taught at Edinburgh University, and returned to Germany to settle down after retirement. First of all, briefly introduce life.
Bohr, N. (niels henrik david bohr 1885 ~ 1962)? Danish physicist, founder of Copenhagen School. 1885 1903/kloc-0 was born in Copenhagen on October 7th, and entered the Department of Mathematics and Natural Sciences of the University of Copenhagen, majoring in physics. 1907 won the gold medal from the Royal Danish Academy of Science and Literature for his paper on the surface tension of water, and 1909 and11obtained the master of science and doctor of philosophy degrees from the University of Copenhagen in. Then I went to England to study, first in the Cavendish Laboratory hosted by J.J. Tang Musun in Cambridge. A few months later, I moved to Manchester and joined a scientific group headed by E. Rutherford. Since then, I have established a long-term close relationship with Rutherford.
19 13 years, Bohr worked as a physics assistant at Manchester University, 19 16 years as a professor of physics at Copenhagen University, and 19 17 years as an academician of the Royal Danish Academy of Sciences. 1920, he founded the Copenhagen Institute of Theoretical Physics and served as its director. Bohr 1922 won the Nobel Prize in Physics. 1923 received honorary doctorates from Manchester University and Cambridge University. 1937 During May and June, Bohr visited and gave lectures in China. 1939 president of the royal Danish academy of sciences. At the beginning of World War II, Denmark was occupied by German fascists. 1943 Bohr fled to Sweden to escape Nazi persecution. From 65438 to 0944, Bohr participated in the theoretical research related to the atomic bomb in the United States. 1947, the Danish government named Bohr "Lord Riding an Elephant" in recognition of his achievements. 1952, Bohr initiated the establishment of the European Center for Nuclear Research (CERN), and he became the chairman of the center. 65438-0955, participated in the establishment of the Nordic Institute of Theoretical Atomic Physics and served as the director of the management committee. In the same year, Denmark established the Atomic Energy Commission, and Bohr was appointed as its chairman.
Second, scientific achievements.
Bohr started his scientific career from 1905 and engaged in scientific research for 57 years. His research work began in the era when the atomic structure was unknown and ended in the era when atomic science was mature and nuclear physics was widely used. His contribution to atomic science undoubtedly made him one of the greatest physicists who kept pace with Einstein in the first half of the 20th century.
1. Atomic structure theory
In the long paper On Atomic Structure and Molecular Structure published by 19 13, the theory of atomic structure was established, paving the way for atomic physics in the 20th century.
2. Create the famous "Copenhagen School"
192 1 year, the Institute of Theoretical Physics of the University of Copenhagen was established at Bohr's initiative. Bohr led the institute for 40 years. This institute has trained a large number of outstanding physicists, and once became the most important and active academic center in the world during the rise of quantum mechanics, and it still has a high international status.
3. Establish the principle of complementarity
1928, Bohr put forward the complementary viewpoint for the first time, trying to answer some questions of physics research and philosophy at that time. The basic idea is that everything has many different aspects. For the same research object, on the one hand, if you admit some aspects of it, you have to give up others. In this sense, they are "mutually exclusive"; On the other hand, those other aspects cannot be completely abolished, because people must also use them under appropriate conditions. In this sense, they are "complementary".
According to Bohr, it is meaningless to investigate which of the two mutually exclusive and complementary aspects is more "fundamental"; People can only and will get a complete description of things, and all aspects and related conditions must be taken into account.
Bohr thinks that his complementary principle is an infinitely broad philosophical principle. In his view, in order to accommodate and compare "our experience", the concept of causality is not enough, and it must be replaced by a complementary concept, a "broader thinking framework". Therefore, he said, complementarity is a "reasonable promotion" of causality. Especially in his later years, he discussed countless problems in physical science, biological science, social science and philosophy with this view, which had a very important influence on western academic circles.
Bohr's complementary philosophy is supported by many influential scholars, but it is also opposed by other equally influential scholars. Around these issues, there has been an academic debate with few precedents in history. This debate has been going on for decades, and it is still inconclusive. It seems that it is far from over.
4. Achievements in nuclear physics
As a student of Rutherford, Bohr not only studied atomic physics and philosophy related to quantum mechanics, but also paid close attention to nuclear issues. Since 1930s, his institute has devoted more efforts to nuclear physics. In the mid-1930s, he put forward a droplet model of the nucleus, thinking that the particles in the nucleus are a bit like molecules in droplets, their energy obeys some statistical distribution law, and the movement of particles near the "surface" leads to the appearance of "surface tension", and so on. This model can explain some experimental facts and is the first relatively correct nuclear model in history. On this basis, he put forward the concept of compound nucleus in 1936, thinking that low-energy neutrons will interact with many nuclei after entering the nucleus, leading to the disintegration of the nucleus. This rather simple picture of the nuclear reaction mechanism is still useful today.
When L. Maitenaz and O. R. frisch put forward heavy nuclear fission's idea according to O. Hahn's experiment, Bohr and others immediately understood this idea and made a more detailed study of the fission process. Bohr also predicted that uranium -235, not uranium -238, was the cause of slow neutron fission. The paper published by him and J.A. Wheeler in Physical Review 1939 is considered as an important achievement of nuclear physics in this period. As we all know, this research has led to the massive release of nuclear energy.
Third, anecdotes
1. "Not afraid to admit that you are a fool"
Bohr is the leader of the famous Copenhagen school in quantum mechanics. With high prestige, he attracted a large number of outstanding physicists at home and abroad and founded the Copenhagen School. They not only founded the basic theory of quantum mechanics, but also gave a reasonable explanation, which made quantum mechanics get many new applications, such as atomic radiation, chemical bonds, crystal structure, metal state and so on. What is more commendable is that Bohr and his colleagues created the "Copenhagen Spirit" while creating and developing science, which is a unique and strong academic atmosphere of equality, free discussion and close cooperation with each other. Today, many people still say that "Copenhagen spirit" is unique in the international physics field. Someone once asked Bohr, "How do you unite so many talented young people around you?" He replied: "Because I am not afraid to admit my lack of knowledge in front of young people, and I am not afraid to admit that I am a fool." In fact, people's understanding of atomic physics, that is, the so-called quantum theory of atomic systems, began at the beginning of this century and was not completed until the 1920s. However, "from beginning to end, Bohr's highly creative, keen and critical spirit always guided the direction of his career and made it thorough until it was finally completed."
Einstein and Bohr had a long and fierce debate about the theoretical basis of quantum mechanics, but they have always been good friends who respect each other. Bohr spoke highly of this argument, thinking it was his "source of many new ideas", while Einstein spoke highly of Bohr:
"As a scientific thinker, Bohr has such amazing attraction because he has a rare combination of boldness and caution; Few people have this intuitive understanding of hidden things and have such strong critical ability at the same time. He knows the details as well as the basic principles. He is undoubtedly one of the greatest discoverers in the field of science in our time. "
2. Bohr and Einstein's sincere friends
Bohr and Einstein met in 1920. That year, young Bohr gave his first speech in Berlin and forged a friendship with Einstein for 35 years. But it was after they met for the first time that they had differences in understanding and started a lifelong debate. As soon as they meet, they will argue with each other. 1946, Bohr wrote an article for the collection commemorating Einstein's 70th birthday. When the collection was published, Einstein wrote a long answer at the end of the collection, sharply refuting Bohr and others' views. Their argument lasted for 30 years until Einstein died. However, the long-term argument has not affected their profound friendship at all, and they have always cared for and respected each other. Einstein should have won the Nobel Prize a long time ago, but because many people were biased against the theory of relativity at that time, he was not awarded the Nobel Prize in Physics until the autumn of 1922, and decided to award Bohr the Nobel Prize in Physics this year. These two decisions were announced simultaneously. Einstein was on his way to Japan when he passed by Shanghai and learned that he had won the prize. Bohr was deeply disturbed by Einstein's long-term failure to win the Nobel Prize, fearing that he would win the prize before Einstein. Therefore, Bohr was very happy when he learned the news. Write to Einstein on the journey immediately. Bohr is modest. In his letter, he said that he was able to make some achievements because Einstein made a fundamental contribution. So Einstein was able to win the Nobel Prize before him, which he felt was "great happiness". Einstein wrote back immediately after receiving Bohr's letter. The letter said, "Shortly before I left for Japan, I received your warm letter. I can say without exaggeration that it makes me feel as happy as the Nobel Prize. You're worried about getting the bonus before me. I think your worry is particularly lovely-it shows Bohr's true colors. "
Bohr likes Feynman who is not afraid of him.
Feynman was still working in Los Alamos Laboratory in the United States, and his position was very low. During World War II, this laboratory researched, designed and manufactured atomic bombs, so many important physicists have been here. One day, Bohr and his son Bohr Jr. (then their names were Nicholas Baker and Jim Baker respectively) also came. Even for the bosses in the laboratory, Bohr is a god, and everyone wants to see Bohr's style. The meeting with Bohr began, and many people arrived. Feynman sat in a corner and could only see Bohr in the middle of the heads of the two people in front. ...
On the morning of the next meeting, Feynman received a phone call.
"Hello, is this Feynman?"
"yes."
"I'm Jim Baker, and my father and I want to talk to you."
"Me? I'm Feynman, I'm just a (buddy) ... "
"It is for you. Can we meet at 8 o'clock? "
At 8 o'clock, Feynman and Bohr meet in the office. Bohr said: "We have been thinking about how to make the bomb more powerful. The idea is this ... "
Feynman said, "No, this idea doesn't work, it doesn't work ..."
"How about another way?"
"That's better, but there are some stupid things here."
They discussed for about two hours and discussed and debated various ideas. Bohr keeps lighting his pipe because it always goes out.
At last Bohr lit his pipe and said, "I think it's time to call the big shots to discuss."
Xiaobo later explained to Feynman that at the last meeting, his father said to him, "Do you remember the name of the young man sitting in the back? He is the only person here who is not afraid of me. Only he can point out whether my idea is crazy or not. So the next time we discuss ideas, we won't discuss them with people who can only say,' Yes, Mr. Bohr, all these will work'. Call that little guy and we'll discuss it with him first. " Feynman suddenly realized why Bohr called him. Cui Qi (1939-) is a Chinese-American physicist. Born in Henan Province, he studied in Peizheng Middle School in middle school. 1958 went to study in the United States, 1967 received a doctorate in physics from the University of Chicago, and then worked in Bell Laboratories. From 65438 to 0982, he became a professor at Princeton University. 1987 was elected as a member of the National Academy of Sciences.
Cui Qi has made outstanding achievements in physics and electronic engineering. His main research field is the properties of electrons in metals and semiconductors. In 1982, Professor Cui Qi and Professor Stolmer studied electrons under the experimental conditions of strong magnetic field and ultra-low temperature. They pressed gallium arsenide and gallium arsenide chloride semiconductor wafers together, so that a large number of electrons gathered at the junction of the two wafers. They put this chip combination in an ultra-low temperature environment of only one tenth of absolute zero, and then applied a super-strong magnetic field equivalent to one million times the strength of the earth's magnetic field. They found that under this condition, a large number of interacting electrons can form a new quantum fluid, which has some special properties, such as the disappearance of resistance and the strange phenomenon of a small number of electron charges. This abnormal effect is the so-called fractional quantum Hall effect. A year later, Professor laughlin explained their experimental results.
The discovery of electronic quantum fluid phenomenon is a major breakthrough in the field of quantum physics and has made important contributions to the development of new theories in many branches of modern physics. Cui Qi, Stormer and laughlin also won the 1998 Nobel Prize in Physics. Cui Qi also won the famous Franklin Prize. Louis de Broglie (1892- 1987) is a French theoretical physicist. De Broglie was born in a prominent aristocratic family in France. As a teenager, he loved literature and history and obtained a bachelor's degree in literature from the University of Paris. Under the influence of his brother, Maurice de Broglie, a famous X-ray physicist, he turned to theoretical physics, and received his doctorate from the University of Paris on 1924. During World War I, De Broglie served in the military radio station on the Eiffel Tower. 1926 taught at the University of Paris, and 1933 was elected as an academician of the French Academy of Sciences.
After the duality of light waves and particles was discovered, young de Broglie was inspired and boldly extended these duality to material objects. He published three papers in succession in 1923, and made a systematic exposition in his doctoral thesis "Research on Quantum Theory". He believes that physical particles also have the frequency of the periodic process of matter. With the movement of objects, there is a phase wave defined by phase, that is, De Broglie wave. Even his tutor Ron Wan Zhi doesn't believe this new theory without experimental evidence. He just thought this paper was very talented, so he got his doctorate. 1927, Davisson, Meg of Bell Laboratories and Tang Musun of England confirmed that electrons do fluctuate through electron diffraction experiments. De Broglie's theory succeeded as a bold hypothesis, and he won the 1929 Nobel Prize in Physics.
De Broglie wrote a lot about science and philosophy. There are mainly quantum theory, introduction to wave mechanics, matter and light, physics and microphysics. British physicist Paul A.M Dirac (1902- 1984) was born in Bristol, England. 192 1 graduated from Bristol university with a bachelor's degree in electronic engineering. 1926 received a doctorate in physics from Cambridge University. 1930, he was elected as a member of the Royal Society of London. Cambridge University professors from 1932 to 1969. He won the 1933 Nobel Prize in Physics with Schrodinger for establishing quantum mechanics.
1928, he introduced relativity into quantum mechanics and established the Schrodinger equation in the form of relativity, namely the famous Dirac equation. Relativity, quantum and spin, previously seemingly unrelated concepts, are harmoniously combined. On this basis, the "hole" theory is put forward and the existence of positrons is predicted. Predicted the existence of antiparticles, the generation and annihilation of positive and negative electron pairs; The hypothesis that antimatter exists and the vacuum polarization effect are put forward. 1932, Anderson discovered positrons in cosmic rays. Soon, when observing cosmic rays, blackett discovered the phenomenon that electron-positron pairs were produced and annihilated in pairs. Dirac's work initiated the theoretical and experimental study of antiparticle and antimatter.
Dirac is the founder of quantum radiation theory, and Fermi and Fermi independently put forward Fermi-Dirac statistics method. Dirac also published a large number of papers on cosmology, which promoted the development of cosmology research. As early as 193 1, Dirac theoretically predicted that there might be a magnetic monopole. In recent years, the theoretical research and experimental detection of magnetic monopole have made rapid development.
Dirac has done research work in universities in many countries. 1935 gave a lecture in Tsinghua University and was elected as an honorary member of the Chinese Physical Society. Dirac has a high level of mathematics and is called an "ivory tower" scientist. His masterpiece "Principles of Quantum Mechanics" has always been a basic textbook in this field. Enrico Fermi (190 1- 1954) is an Italian-American physicist who was born in Rome. 1922 received a doctorate in physics from the University of Pisa with a monograph on X-rays. At the age of 25, he was a professor of theoretical physics at the University of Rome. At the age of 27, he became a member of the Royal Italian Society. Italy promulgated the fascist racial discrimination law in 1938. Since Fermi's wife is of Jewish descent, he took advantage of the Nobel Prize in Sweden to leave Italy for the United States in June 1938 65438+ 10.
At the beginning of 1926, Fermi and Dirac, a British physicist, respectively deduced the Fermi-Dirac statistics in quantum statistics according to the Pauli exclusion principle. 1928 gives an approximate scheme to describe and calculate the ground state of multi-electron atoms (Thomas-Fermi atom model). 1934 established the theory of β decay and laid the theoretical foundation of weak interaction.
At the beginning of 1934, after Joliot-Curie and his wife bombarded the nucleus with alpha particles to produce artificial radioactive elements, Fermi and his assistant bombarded almost all chemical elements with neutrons instead of alpha particles, and got dozens of radioactive isotopes. Fermi won the Nobel Prize in Physics for discovering neutron nuclear reaction.
Fermi began to explore the possibility of nuclear fission chain reaction in 1939, and built the world's first controllable nuclear fission chain reactor in the University of Chicago on February 2, 1942, and realized the controllable nuclear fission chain reaction for the first time. Fermi then participated in the development of the American atomic bomb.
In the last few years of his life, Fermi was a professor at the Institute of Nuclear Physics of the University of Chicago, engaged in the research of high-energy physics. Fermi has made important contributions to both theoretical physics and experimental physics, which is rare among modern physicists. In memory of him, the element 100 was named americium after him. Werner Karl Heisenberg (190 1- 1976) is a German theoretical physicist and the founder of matrix mechanics. He was born in Zzburg, Urville. From 65438 to 0920, he entered Munich University, studied theoretical physics under the guidance of Sommerfeld, and obtained his doctorate. Later, I went to the University of G? ttingen and worked as Born's assistant. From 65438 to 0927, 26-year-old Heisenberg was appointed as a professor at Leipzig University. 194 1 Professor of Berlin University and Director of Kaiser Wilhelm Institute of Physics. From 65438 to 0946, he went to the University of G? ttingen as the director of Planck Institute of Physics. 1958 director of Planck institute of physics and astrophysics in Munich, Germany, professor of Munich university.
1925, Heisenberg published the first paper on matrix mechanics, Quantum Mechanical Interpretation of Kinematics and Dynamics. He thought that the problems of quantum mechanics could not be directly described by unobservable orbits, but should be described by observable measures such as transition probability. Then, Heisenberg, Born and Iordan studied together and founded matrix mechanics.
Heisenberg put forward the uncertainty principle in 1927, that is, the position and momentum of subatomic particles cannot be measured accurately at the same time. 1928, Heisenberg explained the ferromagnetic problem of matter with the exchange phenomenon of quantum mechanics. 1929, he and Pauli put forward the relativistic quantum field theory. 1932 Heisenberg proposed that protons and neutrons are actually two quantum states of the same particle. In addition, Heisenberg also founded the scattering matrix theory of particle interaction-S matrix theory.
Heisenberg won the 1932 Nobel Prize in Physics for his creation of quantum mechanics. His main works are: physical principles of quantum theory, nuclear physics, physics and philosophy. Austrian theoretical physicist Wolfgang Ernst Pauli (1900- 1958) was born in Vienna. 19 18 entered the university of Munich to study theoretical physics, and under the guidance of sommerfeld, he obtained his doctorate in the thesis "On the Molecular Model of Hydrogen". 1923 ~ 1928, lecturer, University of Hamburg. From 65438 to 0928, he became a professor of theoretical physics at the Federal Institute of Technology in Zurich. Here, he stayed in Switzerland until his death, except for a period of work in the Institute for Advanced Studies in Princeton, USA during the Second World War.
192 1 year, sommerfeld recommended Pauli, who was only 2 1 year old, to write a long summary article on relativity for the Encyclopedia of Mathematical Science. Pauli's paper was highly praised by Einstein himself, and it is still one of the masterpieces of relativity.
After Pauli arrived in Copenhagen, he began to study the anomalous Zeeman effect, and put forward the incompatibility principle in 1925: two or more electrons in an atom cannot be in the same quantum state. This principle solved many problems about atomic structure at that time, so Pauli won the Nobel Prize in Physics in 1945. 1930, Pauli put forward the neutrino hypothesis: in the beta decay of the nucleus, not only electrons are released, but also a neutral particle with extremely small mass and strong penetrating power, which Pauli called "neutron" at that time. This hypothesis solves the problem that angular momentum and energy are not conserved in β decay.
Pauli has made important contributions in almost every field of theoretical physics. Among his many articles on quantum mechanics, the most famous one is General Principles of Wave Mechanics. Aurio and Curie refer to F. Aurio-Curie (1900 ~ 1958) and his wife I. Aurio (1897 ~ 1956).
I. Aurio Curie was born in Paris on September 1897. She is the eldest daughter of Madame Curie. Under the careful cultivation of her mother, she became her mother's favorite experimental assistant after graduating from Paris University on 1920. F I Aurio-Curie was born in March 1900. 1923 graduated with honors from the Paris Institute of Physics and Chemistry. His teacher, Ron Wan Zhi, found him promising and recommended him to work in Madame Curie's laboratory. They got married on June 9 1926 because of their similar interests, and decided to work together to open up a new field of radioactivity in jujube.
193 1 at the end of the year, they began to study the experiment of German physicist W. Porter, that is, bombarding quilts with particles A. At this time, instead of the protons that usually appear in experiments, they released a kind of penetrating ray, which Porter thought was a kind of gamma radiation, which was called iron radiation at that time. Soon, Joliot-Curie and his wife not only easily repeated Potter's experimental results with superb experimental techniques and good equipment. And further observe whether paraffin wax will absorb this radiation. They were surprised to find that the radiation was not absorbed, but strengthened. After identifying the particles flying out of paraffin, it is determined that the particles flying out of paraffin are protons. "It's incredible, if radiation is a photon with a mass close to zero. How can you knock out protons whose mass is 1840 times that of electrons? Great discoveries are just around the corner, but they still follow Porter's wrong thinking that beryllium radiation is Compton effect. 1October 1932+ 18, they published their experimental results and their own opinions. Only one month later, chadwick, a student of Rutherford and a British physicist who was prepared for the concept of neutron, reinterpreted the experiment of Joliot-Curie and his wife, and thought that wave radiation was a neutral particle flow, and the mass of this particle was similar to that of proton. In this way, Rutherford 12 years ago's prediction about the existence of neutrons was confirmed, and chadwick 1935 won the Nobel Prize in physics. It should be said that Aurio and Curie did really important work on the discovery of neutrons, and chadwick himself fully acknowledged this. But the reason why opportunities slip away from them on the edge of great discovery is still in themselves. They admitted afterwards that they didn't know Rutherford's hypothesis about the existence of neutrons at all, and lacked the sensitivity and imagination to make this important discovery. The lesson is that, as experimental physicists, they only bury themselves in their own experiments and don't pay attention to the extensive exchange of academic ideas at the same time. If they don't absorb other people's creative new ideas at any time, that's exactly the case. 1932, before American physicist Anderson discovered positrons, Aurio and Curie had clearly observed positron tracks in the cloud chamber, but they did not seriously study this strange phenomenon and mistakenly thought that it was just electrons moving to radioactive sources. It was not until Anderson presented the positron experiment report that they realized that another important discovery opportunity had been lost.
After two consecutive mistakes, Mr. and Mrs. Joliot-Curie didn't lose heart. They summed up the experience and lessons. 1On May 23rd, 933, through pioneering work, they confirmed that a mode V ray emitted by a needle and a sub-source passed through matter, resulting in positron ice for two months, and then recorded a single positron and its continuous spectrum. They have been insisting on studying this phenomenon. 193465438+1October19, it was found that when aluminum foil was bombarded with α particles produced by polonium, if the radioactive source was removed, "positron emission would not stop immediately. Aluminum foil is still radioactive. Radiation decays exponentially like ordinary radioactive elements. " They emit neutrons and positrons, and finally produce radioactive phosphorus. In the same way, they also found some other artificially generated radioactive substances, which are artificial radioactivity. This is one of the most important discoveries of the 20th century. It is a breakthrough for human beings to change the micro-world, making it possible to use isotopes and atomic energy. Therefore, they won the Nobel Prize in chemistry with 1935.